Nab-paclitaxel Approved in First-line Metastatic NSCLC

The FDA has approved paclitaxel protein-bound particles for injectable suspension, albumin-bound (nab-paclitaxel, Abraxane) for use in combination with carboplatin for the initial treatment of patients with locally advanced or metastatic non–small cell lung cancer (NSCLC) who are not candidates for curative surgery or radiation therapy.

This approval for the first-line treatment of locally advanced or metastatic NSCLC was granted under the provisions of 505(b)(2) of the Food, Drug, and Cosmetic Act. FDA relied on the prior approval of paclitaxel (Taxol) for this indication supported by an additional trial establishing that nab-paclitaxel was as at least as active as paclitaxel when both agents are used in combination with carboplatin.

Protocol CA031

The additional trial (Protocol CA031) was a randomized, open-label, multinational trial that enrolled 1,052 patients with locally advanced or metastatic NSCLC. Patients were randomized to receive nab-paclitaxel at a dose of 100 mg/m2 as a weekly infusion (n = 521) or paclitaxel injection at a dose of 200 mg/m2 as an intravenous infusion every 3 weeks (n = 531). Patients in both treatment arms also received carboplatin at the same dose and schedule (AUC 6 mg • min/mL) every 3 weeks.

The CA031 trial met its primary endpoint demonstrating a statistically significantly higher overall response rate for patients in the nab-paclitaxel arm of 33% (95% CI = 29%–37%) compared to 25% (95% CI = 21%–28%) for patients in the paclitaxel arm (P = .005, chi square test). The absolute increase was in overall response rate was 8% (95% CI = 2%–8%). The durability of responses was similar for responding patients in the two treatment groups, with median response durations of 6.9 and 6.0 months for the nab-paclitaxel and paclitaxel arms, respectively. There was no statistically significant difference in overall survival between the two treatment arms.

Serious adverse reactions occurred in 18% of patients in both treatment arms. The most common serious adverse reactions in the nab-paclitaxel arm were anemia (4%) and thrombocytopenia (3%). ■